I've noticed that lots of my emails are missing. Some have been automatically sent to 'Trash', although I have not requested this to happen, and others have just vanished completely. There is not a particular individual or company that seems particularly at risk, it appears to be totally random. The problem is also getting worse. I am losing lots of important emails from work - many before they have even been read. Can anyone tell me what's going on and how to rectify it?

Thanks